Flexible organic light emitting diode display

ABSTRACT

The organic light emitting diode display may comprise a cover window including a display region and a non-display region that surrounds the display region; a flexible substrate arranged on a lower portion of the cover window, and including a first region that is spaced apart from the cover window and a second region that extends from the first region toward the cover window; and an adhesive layer arranged between the cover window and the flexible substrate to make the cover window and the flexible substrate adhere to each other.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional of U.S. patent application Ser. No.14/605,823, filed on Jan. 26, 2015, which claims priority from and thebenefit of Korean Patent Application No. 10-2014-0103783, filed on Aug.11, 2014, which are hereby incorporated by reference for all purposes asif fully set forth herein.

BACKGROUND Field

Exemplary embodiments of the present invention relate to an organiclight emitting diode display.

Discussion of the Background

A flexible display is a next-generation display that is an informationdelivery medium suited to today's consumer. The flexible display is notonly strong against an external impact, convenient to be carried,lightweight, and small, but also able to be implemented as a panel inany shape. In particular, the flexible display has flexibility enough tobe folded or rolled like a sheet of paper.

The active-matrix organic light emitting diode (AMOLED) display that hascurrently been commercialized is vulnerable to moisture and oxygenexisting in the atmosphere. In order to strengthen the competitivenessof a flexible display using a polymer substrate, there is a need for atechnology to effectively prevent permeation of moisture and oxygen. Ifthe moisture and oxygen are not effectively prevented from permeating,defects, such as discoloration of a polarizing element and deteriorationor oxidization of organic materials and electrodes, for example, mayoccur, which severely reduce the lifespan of the display.

Technology to prevent an inflow of moisture and oxygen to an organiclight emitting diode display may include a sealing agent injectionmethod to inject a sealing agent into a space between a base substrateand a cover window, and an anti-moisture adhesive film attachment methodto attach an adhesive film to a base substrate and a cover window and toseal the edge thereof.

However, in order for the sealing agent injection method to prevent theinflow of oxygen and moisture, it may be required for the sealing agentto cover a part of one face of the base substrate. Accordingly, in thecase of adopting the sealing agent injection method, the thickness ofthe organic light emitting diode display is increased as large as thethickness of the sealing agent that covers a part of one face of thebase substrate.

In the same manner, in order for the anti-moisture adhesive filmattachment method to prevent the inflow of oxygen and moisture, it maybe required for the anti-moisture adhesive film to cover a part of oneface of the base substrate. Accordingly, in the case of adopting theanti-moisture adhesive film attachment method, the thickness of theorganic light emitting diode display is increased as large as thethickness of the anti-moisture adhesive film that covers a part of oneface of the base substrate.

SUMMARY

Exemplary embodiments of the present invention provide an organic lightemitting diode display having an improved sealing structure which canreliably prevent an inflow of moisture and oxygen while not increasingthe overall thickness by using a base substrate that constitutes theorganic light emitting diode display.

Additional advantages, subjects, and features of the invention will beset forth in part in the description which follows and in part willbecome apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention.

An exemplary embodiment of the present invention discloses an organiclight emitting diode display, including a cover window including adisplay region and a non-display region that surrounds the displayregion; a flexible substrate arranged on a lower portion of the coverwindow, and including a first region that is spaced apart from the coverwindow and a second region that extends from the first region toward thecover window; and an adhesive layer arranged between the cover windowand the flexible substrate to make the cover window and the flexiblesubstrate adhere to each other.

An exemplary embodiment of the present invention also discloses anorganic light emitting diode display including a cover window includinga display region and a non-display region that surrounds the displayregion; a flexible substrate arranged on a lower portion of the coverwindow to be spaced apart from the cover window, and including a firstregion and a second region that extends from the first region; and asealing agent filling a space between the second region of the flexiblesubstrate and the cover window.

According to exemplary embodiments of the present invention, at leastthe following effects can be achieved.

The flexible organic light emitting diode display according to exemplaryembodiments of the present invention has a sealing structure thatprevents the inflow of moisture and oxygen to the flexible substrateconstituting the display. Accordingly, quality deterioration due to theinflow of moisture and oxygen can be prevented, and the thickness of theflexible organic light emitting diode display is not increased becauseof the sealing structure.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention, andtogether with the description serve to explain the principles of theinvention.

FIG. 1 is a schematic exploded perspective view of an organic lightemitting diode display according to exemplary embodiments of the presentinvention.

FIG. 2 is a schematic cross-sectional view taken along line II-II′ ofFIG. 1.

FIG. 3 is a pixel circuit diagram of a display panel assemblyillustrated in FIG. 1.

FIG. 4 is a schematic partial enlarged cross-sectional view of a displaypanel assembly illustrated in FIG. 1.

FIG. 5 is a schematic cross-sectional view of an organic light emittingdiode display according to exemplary embodiments of the presentinvention.

FIG. 6 is a schematic cross-sectional view of an organic light emittingdiode display according to exemplary embodiments of the presentinvention.

FIG. 7 is a schematic cross-sectional view of an organic light emittingdiode display according to exemplary embodiments of the presentinvention.

FIG. 8 is a schematic cross-sectional view of an organic light emittingdiode display according to exemplary embodiments of the presentinvention.

FIG. 9 is a schematic cross-sectional view of an organic light emittingdiode display according to exemplary embodiments of the presentinvention.

FIG. 10 is a schematic cross-sectional view of an organic light emittingdiode display according to exemplary embodiments of the presentinvention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Features of the inventive concept and methods of accomplishing the samemay be understood more readily by reference to the following detaileddescription of preferred embodiments and the accompanying drawings. Theinventive concept may, however, be embodied in many different forms andshould not be construed as being limited to the embodiments set forthherein. Rather, these embodiments are provided so that this disclosurewill be thorough and complete and will fully convey the concept of theinventive concept to those skilled in the art, and the inventive conceptwill only be defined by the appended claims.

In the drawings, the thickness of layers and regions are exaggerated forclarity. As used herein, the term “and/or” includes any and allcombinations of one or more of the associated listed items.

It will be understood that when an element or layer is referred to asbeing “on,” “connected to” or “coupled to” another element or layer, theelement or layer can be directly on, connected or coupled to anotherelement or layer or intervening elements or layers. In contrast, when anelement is referred to as being “directly on,” “directly connected to”or “directly coupled to” another element or layer, there are nointervening elements or layers present. As used herein, connected mayrefer to elements being physically, electrically and/or fluidlyconnected to each other. Like numbers refer to like elements throughout.As used herein, the term “and/or” includes any and all combinations ofone or more of the associated listed items. It will be understood thatfor the purposes of this disclosure, “at least one of X, Y, and Z” canbe construed as X only, Y only, Z only, or any combination of two ormore items X, Y, and Z (e.g., XYZ, XYY, YZ, ZZ).

It will be understood that, although the terms first, second, third,etc., may be used herein to describe various elements, components,regions, layers and/or sections, these elements, components, regions,layers and/or sections should not be limited by these terms. These termsare only used to distinguish one element, component, region, layer orsection from another element, component, region, layer or section. Thus,a first element, component, region, layer or section discussed belowcould be termed a second element, component, region, layer or sectionwithout departing from the teachings of the invention.

Spatially relative terms, such as “below,” “lower,” “under,” “above,”“upper” and the like, may be used herein for ease of description todescribe the relationship of one element or feature to anotherelement(s) or feature(s) as illustrated in the figures. It will beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation, in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”relative to other elements or features would then be oriented “above”relative to the other elements or features. Thus, the exemplary term“below” can encompass both an orientation of above and below. The devicemay be otherwise oriented (rotated 90 degrees or at other orientations)and the spatially relative descriptors used herein interpretedaccordingly.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used in thisspecification, specify the presence of stated features, integers,operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components, and/or groups thereof.

Exemplary embodiments will hereinafter be described with reference tothe accompanying drawings.

FIG. 1 is a schematic exploded perspective view of an organic lightemitting diode display according to a first exemplary embodiment of thepresent invention. FIG. 2 is a schematic cross-sectional view takenalong line II-II′ of FIG. 1.

Referring to FIGS. 1 and 2, a flexible organic light emitting diodedisplay 1 may be configured to include a display panel assembly 50 fordisplaying an image, a cover window 10 positioned on an outside of adisplay surface of the display panel assembly 50, a touch screen panel40 attached to the display surface of the display panel assembly 50, apolarizing element 30 arranged between the touch screen panel 40 and thecover window 10, and a base substrate 60 arranged on a lower portion ofthe display panel assembly 50.

Further, the flexible organic light emitting diode display 1 may includeadhesive layers 20 a, 20 b, and 20 c. The adhesive layer 20 a may bearranged between the display panel assembly 50 and the cover window 10.The adhesive layer 20 a may also be arranged between the touch screenpanel 40 and the cover window 10. The adhesive layer 20 b may bearranged between the touch screen panel 40 and the display panelassembly 50. The adhesive layer 20 c may be arranged between the displaypanel assembly 50 and the base substrate 60.

The cover window 10 may be positioned on the outside of the displaysurface of the display panel assembly 50 to protect the display panelassembly 50 against external impacts or scratches. The cover window 10may be formed of a transparent material, such as transparent plastic.The cover window 10 may include a display region 12 in which an image ofthe display panel assembly 50 can be visually recognized and anon-display region 11 (shown in FIG. 2) that surrounds the displayregion 12. The non-display region 11 (in FIG. 2) may be configured tohide a portion of the display region 12 in which an image is notdisplayed.

The adhesive layers 20 a, 20 b, and 20 c may include acrylic resin thatis cured by UV rays. However, aspects need not be limited thereto suchthat the adhesive layers 20 a, 20 b, and 20 c may be cured orcrosslinked by other wavelengths of light/radiation, by heat, and/or bychemicals.

The adhesive layer 20 a, which is initially a liquid or paste, may bespread on the cover window 10, and then may be cured by UV rays afterthe base substrate 60, the display panel assembly 50, the touch screenpanel 40, and the polarizing element 30, are stacked thereon. Theadhesive layer 20 a may include a main body portion B2Oa and anextension portion E20 a that extends away from the main body portion B20a. In comparative examples of existing flexible organic light emittingdiode display 1, the adhesive layer 20 a is composed of the main bodyportion B20 a only. However, according to the organic light emittingdiode display 1 of an exemplary embodiment of the present invention, theadhesive layer 20 a may include the main body portion B20 a and theextension portion E20 a.

The adhesive layer 20 b, which is initially a liquid or paste, may bespread on the touch screen panel 40, and then may be cured by UV raysafter the base substrate 60, the display panel assembly 50, thepolarizing element 30, and the cover window 10 are stacked thereon. Thesize or area of the adhesive layer 20 b may correspond to the size orarea of the main body portion B20 a of the adhesive layer 20 a. Theadhesive layer 20 b is spread on the face of the touch screen panel 40,and may have the same area as the area of the touch screen panel 40. Themain body portion B20 a may have the same area as the area of the touchscreen panel 40.

The adhesive layer 20 c, which is initially a liquid or paste, may bespread on the display panel assembly 50, and then may be cured by UVrays after the base substrate 60, the touch screen panel 40, thepolarizing element 30, and the cover window 10 are stacked thereon. Theadhesive layer 20 c is spread on the face of the display panel assembly50, and may have the same area as the area of the display panel assembly50.

The polarizing element 30 may change the optical axis of light that isemitted to the outside through the display panel 120. The polarizingelement 30 may have a structure in which a transparent protection filmis stacked on one face or both faces of a polarizer. The polarizer maybe made of polyvinyl alcohol (PVA)-based resin. More specifically, thepolarizing element 30 may have a structure in which a triacetylcellulose(TAC) protection film adheres to a polarizer. The polarizer may have astructure in which PVA-based molecular chains are aligned in a constantdirection and an iodine-based compound or dichroic polarizing materialis included. In general, the polarizer and the protection film mayadhere to each other by water-based adhesives, for example, a polyvinylalcohol-based aqueous solution. However, the polarizing element 30 isnot limited thereto, and polarizing elements having various structuresmay be used.

The touch screen panel 40 may convert a contact position of the organiclight emitting display 1 that is in direct contact with a hand or anobject into an electric signal. Accordingly, the instruction contentsthat are selected at the contact position may be received as an inputsignal. The touch screen panel 40 may be a flexible touch screen panel.The touch screen panel 40 may adopt various touch types, such as acapacitive type and a resistance type.

The display panel assembly 50 may display an image. The display panelassembly 50 may include organic light emitting elements. The displaypanel assembly 50 will be described later, with reference to FIG. 4.

The base substrate 60 may be positioned on the lower portion of thedisplay panel assembly 50, and may protect the display panel assembly50. The base substrate 60 may include, for example, a polymer film.

For example, the base substrate 60 may be made of any one polymerselected from the group including polyethylene terephthalate (PET),polyethylene naphthalate (PEN), polyethylene sulfide (PES), polyethylene(PE), urethane, polycarbonate, and polyimide (PI).

The thickness of the base substrate 60 may be equal to or larger than 25μm and equal to or smaller than 300 μm. If the thickness of the basesubstrate 60 is smaller than 25 μm, it is too thin to serve as a lowerprotection film for protecting a lower portion of the flexible organiclight emitting diode display 1. If the thickness of the base substrate60 is larger than 300 μm, it may be difficult for the organic lightemitting diode display to have flexibility.

The base substrate 60 may be an organic/inorganic composite film thatprevents an inflow of external oxygen and moisture. Theorganic/inorganic composite film may have a structure in which at leastone organic protection film layer is alternately stacked with at leastone inorganic protection film layer. The inorganic protection film mayprevent an inflow of oxygen and moisture, and the organic protectionfilm may improve impact resistance.

The inorganic protection film may be made of silicon oxide (SiO₂),silicon nitride (Si_(X)N_(Y)), silicon oxynitride (SiON), aluminum oxide(AlO_(X)), aluminum nitride (AlN), TIO, or ZnO, but is not limitedthereto.

A monomer or polymer thin film may be used as the organic protectionfilm. The monomer may be provided by using acrylate monomer,phonylacetylene, diamine and dianhydride, siloxane, silane, or parylene,but is not limited thereto.

As shown in FIG. 2, the base substrate 60 may include a first region 61that corresponds to an area of the display panel assembly 50, and asecond region 62 that extends from the first region 61. The first region61 is spaced apart from the cover window 10 at a predetermined interval,but the second region 62 is bent toward the cover window 10 to adhere tothe cover window 10. The end of the second region 62 may adhere to thenon-display region 11 of the cover window 10.

The extension portion E20 a of the adhesive layer 20 a may adhere thesecond region 62 of the base substrate 60 to the cover window 10. Inother words, the second region 62 of the base substrate 60 may adhere tothe extension portion E20 a of the adhesive layer 20 a. The adhesivelayer 20 c may adhere the first region 61 of the base substrate 60 tothe display panel assembly 50.

The second region 62 of the base substrate 60 may cover the side face ofthe display panel assembly 50, and may be bent toward the cover window10 to contact to the extension portion E20 a of the adhesive layer 20 a.As stated above, in the flexible organic light emitting diode display 1,the first region 61 of the base substrate 60 may include ananti-moisture adhesive film or may not be covered by a sealing agent.Accordingly, in comparison to the existing sealing agent injectionmethod or anti-moisture adhesive film attachment method, the thicknessof the anti-moisture adhesive film that covers the first region 61 orthe thickness of the sealing agent can be reduced.

FIG. 3 is a pixel circuit diagram of the display panel assembly 50illustrated in FIG. 1, and FIG. 4 is a schematic partial enlargedcross-sectional view of the display panel assembly 50 illustrated inFIG. 1.

Referring to FIGS. 3 and 4, a pixel may include an organic lightemitting diode L1 and driving circuit portion T1, T2, and C1. Theorganic light emitting diode L1 may include a pixel electrode 591, anorganic light emitting layer 592, and a common electrode 593. Thedriving circuit portion T1, T2, and C1 may include at least two thinfilm transistors (a switching transistor T1 and a driving transistor T2)and at least one capacitor C1.

One of the pixel electrode 591 and the common electrode 593 may be anelectron injection electrode, and the other may be a hole injectionelectrode. If electrons and holes are injected into the organic lightemitting layer 592, they are combined to generate excitions, and as theexcitions emit energy, light emission is performed.

The switching transistor T1 is connected to a scan line SL1 and a dataline DL1, and transmits a data voltage that is input from the data lineDL1 to the driving transistor T2 according to a switching voltage thatis input to the scan line SL1. The capacitor C1 is connected to theswitching transistor T1 and a power supply line VDD, and stores avoltage that corresponds to a difference between the voltage that istransmitted from the switching transistor T1 and the voltage that issupplied to the power supply line.

The driving transistor T2 is connected to the power supply line VDD andthe capacitor C1 to supply output current IOLED that is proportional tothe square of a difference between the voltage stored in the capacitorC1 and a threshold voltage to the organic light emitting diode L1. Thus,the organic light emitting diode L1 emits light with a strength that isproportional to the output current IOLED.

Referring to FIG. 4, the driving transistor T2 may include asemiconductor layer 581, a gate electrode 583, and a source/drainelectrode 582, and the pixel electrode 591 may be connected to a drainelectrode 235 of the driving transistor T2. The pixel electrode 591 maybe formed of a metal layer that may be configured to reflect light, andthe common electrode 593 is formed of a transparent conductive layerthat may be configured to transmit light. The light that may begenerated from the organic light emitting layer 592 may be reflected bythe pixel electrode 591, and may penetrate the common electrode 593 andan encapsulation substrate 57 to emit out of the display panel assembly50.

The display panel assembly 50 may include a display substrate 51, asemiconductor layer 581, a buffer layer 52, a gate electrode 583, a gateinsulating layer 53, a source/drain electrode 582, an interlayerinsulating layer 54, a planarization layer 55, a pixel defining layer56, and an encapsulation substrate 57. A touch screen panel 40 (inFIG. 1) may be arranged on the encapsulation substrate 57.

The display substrate 51 and the encapsulation substrate 57 may beformed of a polymer film. For example, the display substrate 51 may bemade of polyimide (PI). Like the second region 62 of the base substrate60, the display substrate 51 may be bent to extend toward the coverwindow 10, and may contact the extension portion E20 a of the adhesivelayer 20 a. In other words, the concept of bending and extending theflexible substrate toward the cover window 10 is not limited to the basesubstrate 60 illustrated in FIG. 1, but can extend to the displaysubstrate 51. Further, within the range of technical idea according tothe first exemplary embodiment of the present invention, both thedisplay substrate 51 and the base substrate 60 may be bent and extendedtoward the cover window 10. In this case, the adhesive layer 20 c may bedisposed between the extension portions of the display substrate 51 andthe base substrate 60. That is, the adhesive layer 20 c is interposedbetween the extension portions of the display substrate 51 and the basesubstrate 60, so the moisture and oxygen inflow prevention may befurther improved.

A plurality of signal lines (including scan lines and data lines) and aplurality of pixels may be positioned in the display region of thedisplay substrate 51, and a plurality of metal wires (not illustrated)that are connected to the plurality of signal lines may be positioned inthe pad region.

The display panel assembly 50 may include a first integrated circuitchip (not illustrated) that is mounted on the pad region using achip-on-glass (COG) method. The first integrated circuit chip (notillustrated) may include any one of a scan driving unit and a datadriving unit. The scan driving unit may supply scan signals to theplurality of pixels through scan lines, and the data driving unit maysupply data signals to the plurality of pixels through data lines.

The encapsulation substrate 57 may be smaller than the size of thedisplay substrate 51. The encapsulation substrate 57 may be attached tothe display region of the display substrate 51. The display substrate 51and the encapsulation substrate 57 may be integrally bonded to eachother by a sealing agent (not illustrated) spread along the edge of theencapsulation substrate 57.

The encapsulation substrate 57 may seal the pixels to protect the pixelsagainst the external atmosphere including moisture and oxygen.Additionally or alternatively, instead of the encapsulation substrate57, a thin film encapsulation layer, in which at least one organic layerand at least one inorganic layer are alternately laminated one by one,may be provided.

The plurality of pixels provided on the display substrate 51 may emitlight toward the encapsulation substrate 57, and an outer face of theencapsulation substrate 57 may be a display surface of the display panelassembly 50. The touch screen panel 40 is attached to the outer face ofthe encapsulation substrate 57 and overlaps the display region. Thetouch screen circuit film (not illustrated) may be electricallyconnected to electrodes of the touch screen panel 40. The touch screencircuit film (not illustrated) may be positioned on an upper portion ofthe pad region.

The buffer layer 52 may be formed on the display substrate 51. Thebuffer layer 52 may be formed of, for example, a silicon nitride layer,a silicon oxide layer, a silicon oxynitride layer, or a multilayerthereof.

The semiconductor layer 581 may be formed by depositing amorphoussilicon on an upper portion of the buffer layer 52, patterning, and thencrystallizing the amorphous silicon.

The gate insulating layer 53 may be formed on the semiconductor layer581.

The gate electrode 583 may be formed on the gate insulating layer 53 inthe region that corresponds to the semiconductor layer 581. The gateinsulating layer 53 may be, for example, a silicon oxide layer, asilicon nitride layer, a silicon oxynitride layer, or a multilayerthereof. A source region 581 c and a drain region 581 a may be formed byinjecting a conductive impurity into the semiconductor layer 581 usingthe gate electrode 583 as a mask. In this case, a channel region 581 bis defined between the source/drain regions 581 a and 581 c.

The interlayer insulating layer 54 may be formed on an upper portion ofthe gate electrode 583 over the whole surface of the display substrate51. The interlayer insulating layer 54 may be, for example, a siliconoxide layer, a silicon nitride layer, a silicon oxynitride layer, or amultilayer thereof.

A contact hole H1 may be formed to penetrate the gate insulating layer53 and the interlayer insulating layer 54. The contact hole H1 mayexpose the source/drain regions 581 a and 581 c.

The source/drain electrodes 582 may be formed by laminating andpatterning a conductive layer on the substrate on which the contact holeH1 is formed. The source/drain electrodes 582 are connected to thesource/drain regions 581 a and 581 c through the contact hole H1.

The planarization layer 55 may be formed on an upper portion of thesource/drain electrode 582 over the whole surface of the substrate. Theplanarization layer 55 may be formed, for example, of a kind of materialselected from the group including polyimide, benzocyclobutene seriesresin, and acrylate.

A via hole H2 that exposes the source/drain electrodes 582 may be formedon the planarization layer 55. The source/drain electrodes 582 that areexposed by the via hole H2 are connected to the pixel electrode 591formed on the planarization layer 55.

The pixel electrode 591 may be made of, for example, ITO or IZO, and mayinclude a reflective layer that is made of metal having thecharacteristics of high reflectivity, such as Al, Al—Nd, or Ag. In acase of bottom emission, a reflective layer may not be included, and oneof ITO and IZO, which are transparent conductive layers, may be formed.

An opening is formed by forming and patterning the pixel defining layer56 on the pixel electrode 591. The pixel defining layer 56 serves todivide the plurality of pixels. The pixel defining layer 56 may beformed of a kind of material selected from, for example, the groupincluding polyimide, benzocyclobutene series resin, and acrylate.

The pixel circuit illustrated in FIG. 3 and the cross-sectionalstructure of the display panel assembly 50 illustrated in FIG. 4 aremerely exemplary, and the organic light emitting diode display 1according to the first embodiment can be diversely modified withoutbeing limited to the above-described example.

FIG. 5 is a schematic cross-sectional view of an organic light emittingdiode display according to a second exemplary embodiment of the presentinvention.

Referring to FIG. 5, a flexible organic light emitting diode displayaccording to a second exemplary embodiment of the present invention isdifferent from the flexible organic light emitting diode display of FIG.2 on the point that the second region 62 of the base substrate 60 is notbent toward the cover window 10, but is spaced apart from the coverwindow 10 in the same manner as the first region 61. That is, the secondregion 62 horizontally extends from the first region 61 without beingbent, and forms a space with the cover window 10.

The flexible organic light emitting diode display according to a secondexemplary embodiment of the present invention is also different fromthat of FIG. 2 on the point that a sealing agent 70 fills the spacebetween the second region 62 and the cover window 10. That is, thesealing agent 70 fills the space between the upper face of the basesubstrate 60 of the second region 62 and the lower face of the coverwindow 10. The sealing agent 70 may be made of a material that canintercept an inflow of moisture and oxygen.

Since the second region 62 horizontally extends and the sealing agent 70is injected into the space between the second region 62 and the coverwindow 10, the side face of the display panel assembly 50 may preventthe inflow of moisture and oxygen. Further, since the sealing agent 70does not cover the first region 61 and the lower face of the basesubstrate 60 of the second region, the increase of the thickness that iscaused by a coating layer of the sealing agent 70 does not occur.

The adhesive layer 20 a is spread on the cover window 10. The lower faceof the cover window 10 and one face of the adhesive layer 20 a maydirectly adhere to each other, and the other face of the adhesive layer20 a may directly adhere to an upper face of the polarizing element 30.A side face of the adhesive layer 20 a that connects the one face andthe other face thereof may be covered by the sealing agent 70.

In the same manner, one face of the polarizing element 30 may bedirectly attached to a lower face of the adhesive layer 20, and theother face thereof may directly adhere to the upper face of the touchscreen panel 40. A side face of the polarizing element 30 may be coveredby the sealing agent 70.

In the same manner, one face of the touch screen panel 40 may beattached to a lower face of the polarizing element 30, and the otherface thereof may directly adhere to the upper face of the adhesive layer20 b. A side face of the touch screen panel 40 may be covered by thesealing agent 70.

In the same manner, a lower face of the display panel assembly 50 maydirectly adhere to the upper face of the adhesive layer 20 c, and a sideface thereof may be covered by the sealing agent 70. An upper face ofthe display panel assembly 50 may include a region that is covered bythe sealing agent 70 and a region that adheres to the adhesive layer 20c.

The upper face of the adhesive layer 20 c may adhere to the lower faceof the display panel assembly 50, the lower face thereof may adhere tothe first region 61 of the base substrate 60, and the side face thereofmay be covered by the sealing agent 70.

Like the second region 62 of the base substrate 60, the displaysubstrate 51 of the display panel assembly 50 may extend horizontally,and the sealing agent 70 may be injected into the space between thedisplay substrate 51 and the cover window 10.

Further, through combination of the first embodiment and the secondembodiment, the sealing agent 70 may be injected into the space betweenthe second region 62 of the base substrate 60 and the cover window 10,and then the second region 62 may be bent to extend toward the coverwindow 10.

That is, referring to FIG. 6 that is a schematic cross-sectional view ofan organic light emitting diode display according to a third exemplaryembodiment of the present invention, the display substrate 51 mayhorizontally extend, the sealing agent 70 may be injected into the spacebetween the display substrate 51 and the cover window 10, and the secondregion 62 of the base substrate 60 may be bent to extend toward thecover window 10 to adhere to the extension portion E20 a.

FIG. 7 is a schematic cross-sectional view of an organic light emittingdiode display according to a fourth exemplary embodiment of the presentinvention.

Referring to FIG. 7, a flexible organic light emitting diode displayaccording to a fourth exemplary embodiment of the present invention isdifferent from the flexible organic light emitting diode display of FIG.5 in that the adhesive layer 20 a is configured to include a main bodyportion B20 a and an extension portion E20 a that horizontally extendsfrom the main body portion B20 a.

An upper face of the extension portion E20 a of the adhesive layer 20 amay adhere to the lower face of the cover window 10, a side face thereofmay be covered by the sealing agent 70, and a lower face thereof mayinclude a region that is covered by the sealing agent 70.

FIG. 8 is a schematic cross-sectional view of an organic light emittingdiode display according to a fifth exemplary embodiment of the presentinvention.

Referring to FIG. 8, a flexible organic light emitting diode displayaccording to a fifth exemplary embodiment of the present invention isdifferent from the flexible organic light emitting diode display of FIG.2 on the point that the adhesive layer 20 a includes only the main bodyportion B20 a, and the second region 62 of the base substrate 60 adheresto the cover window 10 by an adhesive layer 20 d that is spaced apartfrom the main body portion B20 a on the same plane.

Instead of extending the adhesive layer 20 a and making the secondregion 62 that is bent to extend toward the cover window 10 adhere tothe extension portion E20 a as in FIG. 2, the second region 62 of thebase substrate 60 may adhere to the cover window 10 by using a separateadhesive layer 20 d that is separated or spaced apart from the adhesivelayer 20 a.

FIG. 9 is a schematic cross-sectional view of an organic light emittingdiode display according to a sixth exemplary embodiment of the presentinvention.

Referring to FIG. 9, a flexible organic light emitting diode displayaccording to a sixth exemplary embodiment of the present invention isdifferent from the flexible organic light emitting diode display of FIG.2 in that both the display substrate 51 of the display panel assembly 50and the base substrate 60 are bent to extend toward the cover window 10,and an adhesive layer 80 exists between the display substrate 51 and theextension portions 62 and 51E of the base substrate 60. The adhesivelayer 80 may extend from the adhesive layer 20 c. Since the adhesivelayer 80 is interposed between the display substrate 51 and theextension portions 51E and 62 of the base substrate 60, the moisture andoxygen inflow prevention can be further improved.

FIG. 10 is a schematic cross-sectional view of an organic light emittingdiode display according to a seventh exemplary embodiment of the presentinvention.

Referring to FIG. 10, a flexible organic light emitting diode displayaccording to a seventh exemplary embodiment of the present invention isdifferent from the flexible organic light emitting diode display of FIG.2 on the point that the base substrate 60 is composed of anorganic/inorganic composite film, and an adhesion interface between aside face of the extension portion E20 a of the adhesive layer 20 a andthe second region 62 of the base substrate 60 is protected by thesealing agent 70.

While the invention has been particularly shown and described withreference to exemplary embodiments thereof, it will be understood bythose of ordinary skill in the art that various changes in provide anddetail may be made therein without departing from the spirit and scopeof the invention as defined by the following claims. The exemplaryembodiments should be considered in a descriptive sense only and not forpurposes of limitation.

What is claimed is:
 1. An organic light emitting diode display,comprising: a cover window comprising a display region and a non-displaysurrounding the display region; a flexible substrate disposed on a lowerside of the cover window, spaced apart from the cover window, andcomprising a first region and a second region extending from the firstregion; and a sealing agent filling a space between the second region ofthe flexible substrate and the cover window.
 2. The organic lightemitting diode display of claim 1, wherein the flexible substrate is adisplay substrate comprising a display panel assembly, the display panelassembly comprising organic light emitting elements.
 3. The organiclight emitting diode display of claim 1, wherein the flexible substrateis disposed on a lower face of a display panel assembly, the displaypanel assembly comprising organic light emitting elements.
 4. Theorganic light emitting diode display of claim 1, further comprising apolarizing element disposed between the cover window and the flexiblesubstrate.
 5. The organic light emitting diode display of claim 1,further comprising a touch panel disposed between the cover window andthe flexible substrate.
 6. The organic light emitting diode display ofclaim 5, further comprising a polarizing element disposed between thecover window and the touch panel.
 7. The organic light emitting diodedisplay of claim 1, further comprising an adhesive layer configured toadhere an element that is disposed between the cover window and theflexible substrate to the cover window.
 8. The organic light emittingdiode display of claim 7, the adhesive layer comprising: a first facedirectly adhering to the cover window; a second face opposite the firstface; and a side face extending from the second face to connect thefirst face and the second face, the side face being covered by thesealing agent.
 9. The organic light emitting diode display of claim 7,the adhesive layer comprising: a first face of the adhesive layerdirectly adhering to the cover window; a second face opposite the firstface directly adhering to an element disposed between the cover windowand the flexible substrate; and a side face extending from the secondface to connect the first face and the second face, the side face beingcovered by the sealing agent.